function [x,y,s] = mask(a,idx,orient,vals)

x = cell(3,1);
y = cell(3,1);
s = cell(3,1);

x{1} = [-1 0 1 0 -1];
y{1} = [0 1 0 -1 0];
s{1} = 'k';

x{2} = [-0.2 -0.15 0 0 0.15 0.2];
y{2} = [-0.45 -0.5 -0.4 0.35 0.45 0.35];
s{2} = 'y';

x{3} = [-0.1 0.15];
y{3} = [0.05 0.05];
s{3} = 'y';
